Stainless Steel Coil Tube — Product Technical Specification
1. Product Overview
The Stainless Steel Coil Tube (Coiltube) is a precision-engineered tubular product manufactured by Wenzhou Jixing Metal Materials Co., Ltd. Unlike conventional straight-length seamless or welded stainless steel tubes, coil tubes are produced in continuous helical or spiral wound configurations, offering exceptional versatility in downstream processing, installation, and storage. This product is designed for high-performance applications in the chemical processing, pharmaceutical, food and beverage, oil and gas, and energy sectors where corrosion resistance, mechanical integrity, and dimensional accuracy are paramount.
Coil tubes are formed through a specialized continuous manufacturing process that yields seamless tubular products in coiled form, eliminating the need for post-production straightening and cutting in many applications. This results in reduced material waste, improved production efficiency, and superior surface quality.
2. Material and Properties
Stainless steel coil tubes are fabricated from austenitic, duplex, and super-austenitic stainless steel grades, each selected to meet specific service environment requirements. The following are the primary material grades offered:
- Austenitic Grades: 304 (UNS S30400), 304L (UNS S30403), 316 (UNS S31600), 316L (UNS S31603), 321 (UNS S32100), 347 (UNS S34700)
- Super-Austenitic Grades: 904L (UNS N08904), 254 SMO (UNS S31803), AL-6XN (UNS N08028)
- Duplex Grades: 2205 (UNS S31803), 2507 (UNS S32750)
Key Mechanical and Physical Properties
| Property | 304 / 304L | 316 / 316L | 321 | 2205 Duplex |
|---|---|---|---|---|
| Yield Strength (MPa) | ≥205 | ≥170 | ≥205 | ≥450 |
| Tensile Strength (MPa) | 515–730 | 485–720 | 515–730 | 550–800 |
| Elongation (%) | ≥40 | ≥35 | ≥40 | ≥15 |
| Chromium Content (%) | 18.0–20.0 | 16.5–18.5 | 17.0–19.0 | 22.0–23.0 |
| Nickel Content (%) | 8.0–10.5 | 10.0–14.0 | 9.0–12.0 | 4.5–6.5 |
| Maximum Service Temperature (°C) | 870 | 870 | 925 | 300 (oxidation) |
| Corrosion Resistance (pH) | 2–12 | 2–13 | 2–12 | 1–14 |
3. Product Specifications
| Parameter | Specification |
|---|---|
| Product Name | Stainless Steel Coil Tube (Coiltube) |
| Manufacturer | Wenzhou Jixing Metal Materials Co., Ltd |
| Outer Diameter (OD) | 6.00 mm – 108.00 mm (custom sizes available) |
| Wall Thickness | 0.50 mm – 8.00 mm |
| Coil Length | Continuous coil, typically 50 m – 500 m per coil |
| Coil Inner Diameter | 300 mm – 600 mm (adjustable per customer requirement) |
| Tolerance on OD | ±0.10 mm to ±0.30 mm (per ASTM A269 / EN 10216) |
| Tolerance on Wall Thickness | ±10% of nominal (minimum ±0.05 mm) |
| Surface Finish | 2B (cold rolled and annealed), BA (bright annealed), No.4 Brushed, Mirror Polish (Ra ≤ 0.4 μm) |
| End Condition | Plain, Beveled (45°), Threaded (per ASME B1.20.1), or Custom |
| Applicable Standards | ASTM A269, ASTM A270, EN 10216-5, EN 10217-7, GB/T 12771, JIS G3459 |
| Packaging | Export-grade wooden pallet with moisture-proof wrapping; coil secured with steel bands |
4. Manufacturing Process
The production of stainless steel coil tubes at Wenzhou Jixing Metal Materials Co., Ltd follows a rigorous, multi-stage manufacturing process designed to ensure dimensional precision, metallurgical integrity, and surface quality:
- Raw Material Inspection: Ingot or strip material is received and subjected to spectroscopic analysis (OES — Optical Emission Spectroscopy) to verify chemical composition against ASTM or EN specifications.
- Hot Rolling and Annealing: Billet material is hot-rolled into seamless tube blanks and subsequently annealed to achieve a fully austenitic microstructure and relieve residual stresses.
- Cold Drawing / Cold Rolling: The hot-rolled tube is cold-drawn through precision dies or cold-rolled to achieve the final outer diameter and wall thickness tolerances. This step significantly improves surface finish and mechanical properties.
- Solution Annealing: Tubes are heat-treated at temperatures between 1040 °C and 1150 °C (depending on grade), followed by rapid water quenching. This restores corrosion resistance, eliminates sensitization, and achieves a uniform grain structure.
- Pickling and Passivation: Annealed tubes are pickled in nitric-hydrofluoric acid mixtures to remove scale and oxide layers, followed by passivation to establish a protective chromium oxide film (minimum 1000 Å thickness).
- Coiling Operation: The finished tube is coiled using a high-precision winding system. The intelligent bridge crane system — a key asset in the production line — facilitates automated coil handling, ensuring no mechanical damage during the coiling and storage process. The crane's intelligent load-sensing and anti-sway control systems guarantee safe and efficient material handling throughout the production line.
- Final Quality Inspection: Each coil undergoes dimensional measurement (laser diameter gauging), ultrasonic testing (UT) for internal defects, hydrostatic pressure testing (per ASTM A269, minimum 20,000 psi or 138 MPa), and visual surface inspection.
- Packaging and Dispatch: Qualified coils are wrapped in moisture-resistant film, placed on export-grade wooden pallets, secured with steel strapping, and prepared for shipment.
5. Applications
Stainless steel coil tubes find extensive use across a broad spectrum of industries:
- Chemical Processing: Heat exchanger tubes, reactor piping, and corrosion-resistant process lines handling aggressive acids, alkalis, and chlorides.
- Pharmaceutical and Biotechnology: CIP (Clean-in-Place) and SIP (Sterilize-in-Place) piping systems, bioreactor assemblies, and fluid transfer lines requiring sanitary-grade surfaces (Ra ≤ 0.5 μm).
- Food and Beverage: Dairy processing equipment, brewing systems, and food-grade conveying systems compliant with FDA and EHEDG standards.
- Oil and Gas: Subsea production lines, sour service environments (H₂S-resistant grades such as 316L, 904L, and 2507), and offshore platform tubing.
- Energy and Power Generation: Solar thermal collector tubes, nuclear reactor coolant loops, and high-temperature exhaust systems.
- Automotive and Aerospace: Turbocharger exhaust manifolds, fuel lines, and high-temperature structural tubing.
- Medical Devices: Endoscopy instrument shafts, surgical tool handles, and implant manufacturing feedstock.
6. Quality Certifications and Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains comprehensive quality management systems and holds the following certifications:
- ISO 9001:2015 — Quality Management System certification ensuring consistent product quality and process control.
- ISO 14001:2015 — Environmental Management System certification for sustainable manufacturing practices.
- ISO 45001:2018 — Occupational Health and Safety Management System certification.
- ASME Certificate of Conformity — For products manufactured per ASME standards (BPVC Section VIII).
- EN 10204 3.1 Certificate — Third-party material inspection and test certification.
- Mill Test Reports (MTR) — Provided with every shipment, documenting chemical composition, mechanical properties, and non-destructive test results.
- NADCAP / PED 2014/68/EU — Available upon request for pressure equipment and aerospace applications.
7. Unique Selling Points
- Continuous Coil Format: Eliminates butt-weld joints, reducing leak risk and improving system reliability in critical service.
- Intelligent Production Line: The integration of an intelligent bridge crane system in the coil tube production line enables automated, damage-free coil handling, enhancing throughput while maintaining product integrity.
- Wide Grade and Size Range: From 6 mm to 108 mm OD with wall thicknesses from 0.5 mm to 8 mm, covering austenitic, super-austenitic, and duplex grades.
- Sanitary Surface Finishes: Mirror-polished surfaces (Ra ≤ 0.4 μm) suitable for pharmaceutical and food-grade applications without additional post-processing.
- Full Traceability: Each coil is individually traceable from raw material mill certificate through final dispatch, supported by digital quality documentation.
- Customization Capability: Non-standard dimensions, special end treatments, and custom coil configurations available upon request to meet project-specific requirements.
Supplier Note: Wenzhou Jixing Metal Materials Co., Ltd is committed to delivering high-integrity stainless steel coil tube products backed by rigorous quality control, intelligent manufacturing infrastructure, and comprehensive after-sales technical support. All products are manufactured in strict compliance with applicable international standards and are accompanied by full documentation for regulatory and engineering verification.